1. Field
The present disclosure relates to the manipulation of virtual three-dimensional (3D) objects, and, in one particular example, to constraining virtual 3D objects to each other in virtual 3D space using directed acyclic graphs (DAGs).
2. Related Art
Scenes in animated media productions typically include multiple objects, such as characters or assets. To provide realism, the objects are manipulated to appear to interact with each other in a similar fashion as in the real world. For example, a scene may include a protagonist character moving or otherwise manipulating a prop asset, such as a sword. To achieve this effect, an animator user may manually move the handle of the sword frame-by-frame in virtual three-dimensional (3D) space along with the movement of the character's hand during production. After the images are rendered, the sword appears to move with the movement of the character's hand in the animation.
Media productions typically use graphs to render, animate, or otherwise describe a scene in an animation. Directed acyclic graphs (DAGs) may be used to represent characters and assets. Graphs can include a system of interconnected nodes that perform computations on input data, such as input attributes, and produce output data, such as output attributes. By varying the animation controls that feed into the inputs of an object, an animator user can control the motion, location, and other visual effects of the object.
As media productions create more realistic animations, the complexity and the number of nodes in the graphs used to support these animations also increase. For example, the graph describing a character may become larger and more complex as the character is enhanced to include visual elements and movements that are more realistic. To create a visually appealing animation, it is helpful to produce animated interactions among the complex characters and between characters and props in a realistic manner. Accordingly, an optimized technique for manipulating characters and assets using constraints is described.